Replication by human DNA polymerase-ι occurs by Hoogsteen base-pairing

Deepak T. Nair, Robert E. Johnson, Satya Prakash, Louise Prakash, Aneel K. Aggarwal

Research output: Contribution to journalArticlepeer-review

268 Scopus citations


Almost all DNA polymerases show a strong preference for incorporating the nucleotide that forms the correct Watson-Crick base pair with the template base. In addition, the catalytic efficiencies with which any given polymerase forms the four possible correct base pairs are roughly the same. Human DNA polymerase-ι (hPolι), a member of the Y family of DNA polymerases, is an exception to these rules. hPolι incorporates the correct nucleotide opposite a template adenine with a several hundred to several thousand fold greater efficiency than it incorporates the correct nucleotide opposite a template thymine, whereas its efficiency for correct nucleotide incorporation opposite a template guanine or cytosine is intermediate between these two extremes. Here we present the crystal structure of hPolι bound to a template primer and an incoming nucleotide. The structure reveals a polymerase that is 'specialized' for Hoogsteen base-pairing, whereby the templating base is driven to the syn conformation. Hoogsteen base-pairing offers a basis for the varied efficiencies and fidelities of hPolι opposite different template bases, and it provides an elegant mechanism for promoting replication through minor-groove purine adducts that interfere with replication.

Original languageEnglish (US)
Pages (from-to)377-380
Number of pages4
Issue number6997
StatePublished - Jul 15 2004

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Replication by human DNA polymerase-ι occurs by Hoogsteen base-pairing'. Together they form a unique fingerprint.

Cite this